In many applications, including optical telecommunications, it is often desirable to convert an optical signal into an electrical signal. This can be done by photodetection, whereby the optical signal is linearly absorbed in a semiconductor material to create free carriers that cause an electrical response at nearby biased electrodes. Ideally, well established fabrication techniques for silicon, such as complementary metal-oxide-semiconductor (CMOS), could be used to fabricate an integrated photodetector in silicon. Unfortunately, the energy of the indirect electronic bandgap of silicon (1.1 eV) is too large for linear absorption of the energy of photons in the telecommunication band (0.8 eV).